[lmm]

Most major American cities have terrible traffic and air quality problems already, which are only getting worse as cars get bigger and heavier (and electric cars can be worse). America might need thirty years of densification before some of the high speed rail boosters' ideas make sense, but congestion charging, better zoning rules, and gradual elimination of street parking coupled with improving bus and rail infrastructure made sense thirty years ago and made more sense today. Amsterdam didn't get to be a nice place to live through natural luck or some magic non-Americanness, it took fifty years of gradual improvements and rebuilding, and the fights about it in the '70s were just as bitter as the fights about transport in the US today.

[Lanolderen]

Just quickly gonna shill that carsharing and motorcycles/scooters are a pretty good option as is home office/decentralized offices for many current commuters.

[lmm]

Carsharing doesn't really help with peak time traffic which is the biggest issue. Motorcycles/scooters/e-bikes can work if you can figure out the right incentives to get people to use them. If you can get employers to support working from home that would help hugely, but that's a big if.